Sensor Biochips May Help

With the help of the novel microchip it is possible to find out whether a patient's tumor cells will react to a given drug. The chip, which has been developed at the Technische Universitaet Munich (TUM), Germany, could help with the rapid identification of the most effective medication for the individual patient in future.

Although physicians have numerous cancer drugs at their disposal today, the treatment must be precisely tailored to the patient. If it takes a second or third try to find a drug that works, the patient loses valuable time.

In the future, miniature laboratories could provide fast help. A lab-on-a-chip is a device -- made of glass, for example -- that is just a few millimeters across and has bioelectronic sensors that monitor the vitality of living cells. The chips sit in small wells, known as microtiter plates, and are covered with a patient's tumor cells. A robot changes the culture fluid in each well containing a chip at intervals of just a few minutes. The microsensors on the chip record, among other things, changes in the acid content of the medium and the cells' oxygen consumption; photographs of the process are also taken by a microscope fitted underneath the microtiter plate. All of the data merge in a computer that is connected to the system, and which provides an overview of the metabolic activity of the tumor cells and their vitality.

After the tumor cells have been able to divide undisturbed for a few hours, the robot applies an anti-cancer substance. If their metabolic activity declines over the next day or two, the active substance was able to kill the tumor cells and the drug is effective. Using the microchips, twenty-four active substances or combinations of active substances can be tested simultaneously in this way.